I own a stock DI/O. Definitely a great deal. Even in stock form it improves the sound of sub-$600 CDPs. I agree with Sean about soundstage. Also, the bass is rather boomy in my experience.
Having replaced the DI/O in my main system, I moved it to my second system (headphones). In that system, it has an effect similar to the Stax diffuser or Headroom processer--sounds less like headphones--may relate to soundstage issues noted above. That is a nice effect because it doesn't degrade the sound or change the frequencies as the those processor technologies can.
I haven't heard a modified DI/O, but relatively inexpensive used DACs at current prices here on Audiogon beat the stock DI/O in frequency balance, texture, and soundstage. I have retired mine again in favor of a Muse Model 2 for the headphone system. So, while I consider the DI/O a great deal and hope to use the A/D feature in recording at some point, there are a lot of other great DAC deals out there worth considering as well. Perhaps a trip to Plato's to hear the modified version would make me a convert. . . .
Having replaced the DI/O in my main system, I moved it to my second system (headphones). In that system, it has an effect similar to the Stax diffuser or Headroom processer--sounds less like headphones--may relate to soundstage issues noted above. That is a nice effect because it doesn't degrade the sound or change the frequencies as the those processor technologies can.
I haven't heard a modified DI/O, but relatively inexpensive used DACs at current prices here on Audiogon beat the stock DI/O in frequency balance, texture, and soundstage. I have retired mine again in favor of a Muse Model 2 for the headphone system. So, while I consider the DI/O a great deal and hope to use the A/D feature in recording at some point, there are a lot of other great DAC deals out there worth considering as well. Perhaps a trip to Plato's to hear the modified version would make me a convert. . . .